Needle check valve



. `This in some Aconditions of "oper .standpoint of noise but f the valvestructurein that the the provision lor a valverhaving-a all fluttering` thereof. Another :einem the l in the' hollow stem' Patented Ju'lyr14,` 1942 .Nes

valves and provements in needle vention relates` broadly to more f speeically `to im check valves havi ied therein.

Heretofore checku valves:such` as those tern-11.

ation.` Such chattering and vibrationv isnot onl .is also.detrimental to d.therethrougl1 .i` objects of` the present invention is vide Va valve rneniberfdesigned so th .assist's`l in gllicllngg` foregoing andthe al1 the various `'ohectsare realized. will appear in the following` description, l which considereddn connection with theaccompanying drawing,.sets nibodirnent. oit the invention. 'fiiierablyaccomplish Ythe moiintedtherein, ving a jspider secured thereto `with 'Fi has" pistn sudabiy said pistonjha a spring interposedibetwen thespiderand valve member, for eliminating the valve. `Preferably iluttering` 0f the the piston is,` slib'ably. mounted ofjthe valve member with the spring pressed spideraflixed "to" the fr ee end oi the piston and adapted `to engagea valve coupiing disposed within an end of the valve casing for urging Athe valve mernlierV towards 'its seat. The piston is also arranged sothatit cannot bind within the hollow stem of the valve member and ng a dampening `device embody disagreeable 4from the further is supported 'in such m sists in maintain at .the termination- 3o manner in whichv lowl stem? Il."y

.above anal1 other Referring to the `c1 1 to permit lui Clearaic betwenihe n head Vand base` portions .of the pistonV permits ff'f "fnbpieatienseptember eflegseriallv. 355,641 1 v l claimscrisi-.146i

armer that it'asing the valvein alignment with itszvalve seat, Y -f rawing wherein' the preferred embodiment-of the invention is illustrated, Fig. lfisavertical'"sectional view of theneedle `check valve :embodied in the present invention; Fig. 2` is anendview of-a valvecouplingse'cured within the valve casing; Fig. 3 is a transverse sectional ,view showingA the spider disposed within the` valve chamber, `the section being taken ona planeA indicate'dby line l3---3 ofFig. 1; and Fig. 4 #is atransverse sectional view 'of the needle valve leasing I0 having formed `integrallytherewith` anf inlet: portfll which communicates with a chamber 2in thecasing.;l Extending from the chamber AI2 and in axi al alignment with the inlet Voutlet 4.port I3 which is rnally` .for the reception of la valve port I l `there is an threadedffinte coupling, I4.

A `:valve seatxltis formed in the chamberV needle valve"|"6 `is 4Il which'is adapte e needle valve'IB and preventszthe piston/fromV binding within thehol- While the clearance betweenthe piston 'andvalve stmis'of such a magnitude as d to flow slowly past the piston, it is not' suicient Ato permitfthepistonto` have a vloose or sloppyl iit within'the valvestem.

Byforniing thepston 18 witha convex or arcuate surface,` vthe central portion of thelpiston the only `'partthat is in intimate contact with the inner walls ofthe hollow valve stem I T. The liollowvalve stem and the manuiacutring tolerances to be increased "and preventsV binding between the piston and valve stem, even` though the spider`v 22 may .not hold the piston in exact axial alignment with the hol- It is `sufficient that .only the cen the piston be in intimate contact lowfstem H." tral portion of with the hollow valve stem to insure a proper 

